Dredging and impact on a river

posted Jun 16, 2018, 8:11 AM by jeffery jim

So what is the verdict on riparian when you dredged the riverbank of a floodplain covers with emergent aquatic and semi-aquatic plants? There are 4 main outcomes from maximum probable flood simulation; the flood depth, the velocity, the shear stresses and the power of the stream.

Where most (including myself) are concern of the riparian ecological impact when it comes to watercourse management; it actually has the smallest impact for the overall drop of water level and a mediocre result for flood mitigation.

The drastic change would be the shear stresses (randomly for different ARI cases) on the riverbank when it comes to a combine storm events and the power of the stream for any alternative power. In a good way, this reduces possible scouring/undercutting, erosion and/or sedimentation which increase bank stability and channel integrity.

Remark: This is based on theoretical finding from flood simulation software. Unless proven in slope stability software, this will continue to be a unilateral finding.